Do hives keep making an appearance in your life? If so, you may be curious if food, medication, or an irritant that came in contact with your skin is the culprit. While some cases of hives can be tied to one or more of these three common causes, there may be more uncommon factors behind your hive outbreaks. Things like stress, water, and even tight clothing can trigger eruptions of raised, itchy, red hives (urticaria) on your skin. Check out these eight surprising causes that are easy to overlook.